Running to the grocery store before guests arrive? It's the perfect time -- and place -- to pick up flowers for your table's centerpiece.

Todd Fiscus, owner of Todd Events and Avant Garden in Dallas, says that flowers don't have to be fancy or cost a ton of money, you just need to know how to put them together like a pro. "I buy them at the grocery store, too," he says. Here are his top tips.

Shop the fresh-produce section

"Fill a bowl with pomegranates that you split open with giant clusters of grapes and red apples," he says. "Or take Romanesco [broccoli]... It makes the most beautiful rose shape."

Stick to one color

The key to creating a sophisticated look is to make it monochromatic, such as all red, all white or all green, as in Granny Smith apples mixed with green pears and green figs, he says. "That's what keeps it looking elegant."

Pick three flowers

"You should do no more than three flower types in the same vase," Fiscus says. "One fat flower, one straight flower, and one round flower, to get a better look." For example, hydrangeas are fat; roses, peonies and dahlias are round; straight flowers include snapdragons and gladiolus.

Look for a tight blossom

"The more open the bloom, the closer to the end of life it is," he says. "It's when it's more alluring, but it's also 48 hours from death." Unless you're buying for a party that day, buy flowers that haven't yet opened.

Forage in your own backyard

It's fine to pick up sticks and foliage from the yard for your table, but don't just throw them on the table as is. "Take a painter's bucket and fill it with 1 capful of bleach to 2 gallons of water, then dip your branches or leaves into this, then let them dry completely," he says. That way, you won't have uninvited guests crawling on your table.

Go for scale

Don't just randomly scatter leaves and miniature pumpkins around the plates. "It looks like you swept everything up off the backyard and put it on the table," Fiscus says. Instead, mix elements of different sizes. "The prettiest arrangements have a juxtaposition of something big mixed with something small," he says. "Three fireplace logs with scattered leaves and taper candles are stylish. You have a big thing mixed with little things."

Ellise Pierce is a Dallas freelance writer who blogs at cowgirlchef.com.